package demo1;

public class LeetCode34 {
    public int mySqrt(int x) {
        if (x < 1) return 0;
        int left = 1, right = x;
        while (left < right) {
            long mid = left + (right - left + 1) / 2;
            if (mid * mid <= x) left = (int) mid;
            else right = (int) mid - 1;
        }
        return left;
    }
}
